256 Geological Survey of California. 
The new reactions which I have described in this pape in- 
clude characteristic criteria for all those cases in which it has 
been considered most difficult to pmcicna ey pete and 
rhodium offer no difficulties; the first can always be reqngniae 
with ease by its behavior with chlorid of potassium, and t 
latter by its behavior with caustic alkalies. For the other me per 
I propose here very briefly to recapitulate what I consider the 
chief points of interest here developed 
Ru,Cl,. The characteristic reaction of sesquichlorid 0 
thenium is its beautiful coloration when boiled with ‘povutolils 
of soda. See section third. 
RuCl,. Bichlorid of ruthenium is recognized by its rose- 
i Precipitate with ammonio-chlorid of zinc, as described in 
section seven 
> ‘te t Iridium is best detected by its behavior with proio- 
chlorid of tin and potash. The — ah mode of application 
have been already described in sectio 
PdCl. e reaction of iotcohioria ‘of palladium with ‘etra- 
thionic acid is highly characteristic, —_ cannot well be con- 
founded with any other. See section 
For ascertaining the purity of solutions of iridi ium, particu 
larly as respects ruthenium, the hyposulphite of soda is epacislly 
vs ae as  desoribed at the end of section third. 
ladelphia, May 
SS. 
Arr. XXX.—Progress of the Geological Survey of Califorma. 
Proressor Wurrney, having recently returned from California, is DoW 
engaged in superintending the publication of a portion of the ma ateri 
collected by the Geological Survey of California. He communicates 
speed statement in “regard to the present condition and probable future 
of the Survey :— 
oe interested in the California Survey will already have learned 
ng of its progress from the brief re reports, or letters to the Governor 
of t that Satay which have appeared fide time to time, during the past 
three years, and of which extracts or notices, more or less complete, have 
‘in this awn (See Journal for July, 1863, and May, 1964.) 
No serious opposition has been made to the continuance of the Surveys 
during any of the Levuletive sessions, pat on the pa of economy, 
es aegenent which was urged with a reason than usual before the 
oe, gi ; Since, owing to a variety of causes, ites it is not ne 
essary here to specify, the finances of the State, for the past three or 
_~years, have pote ce pao a condition. The vast extent of area to 
2 explored, the of subjects claiming attentio 
fe to carry-on this work with anything like satisfaction, eve@ 
: which would be deemed ample on the Atlantic side | 
ed, the n, and ae 
y expense of E vaesting on everywhere on the Pacific slope, make it a 
